1. Field of the Invention
The invention relates to a bottom structure of a vehicle body that is suitable for protection against an impact applied upon side collision of a vehicle.
2. Description of the Related Art
Japanese Patent Application Publication JP-A-09-39839 describes a structure in which a floor cross member having a middle portion that bends and thus has a convex shape is provided below a passenger seat so as to extend in the lateral direction of a vehicle body.
According to this structure, when a vehicle is hit from one side thereof and collision impact is applied to the floor cross member from that side of the vehicle, the convex middle portion of the floor cross member further bends upward and thereby inclines the passenger seat towards the lateral center of the passenger compartment, so as to protect the occupant on the passenger seat.
However, according to this technology, because a floor cross member having a bending portion needs to be additionally provided under the passenger seat, the vehicle weight increases, and the structure under the passenger seats becomes complicated.
Meanwhile, there are demands for minimizing the loss of the space under the floor of a vehicle body, in which, for example, a fuel tank is installed.